This invention concerns an automatic watering device for cultivation in pots or the like.
To be more exact the invention concerns a device suitable to feed and wet cultivation substrata correctly in summer and winter and able to ensure a great operating endurance and to be fitted to any container, whether already existing or not, for cultivation purposes.
The automatic watering device according to the invention is especially advantageous in the case of cultivation employing the "high and low tide" system, also called the "ebb and flow" system, whereby the crop is alternately flooded and dried.
In these particular cultivation systems the re-supply of water has to take place only after the existing quantity of water has been wholly exhausted, thus causing in the plant a hydric stress which strengthens the plant and ensures for it a lush and healthy growth.
The state of the art covers manifold devices or systems for cultivation in pots or the like, such devices or systems forming also patent applications in the name of the present applicant.
All the embodiments of the state of the art have the aim of ensuring a long working endurance from the standpoint of the maintaining of the cultivation.
In other words the tendency is to have a means of a great capacity, such as a tank to hold the wetting liquid, and suitable automatic aspiration means to deliver-the liquid continuously and evenly to the cultivation substratum generally arranged above the tank.
The embodiments of the state of the art overcome the above problem thoroughly, even as regards the ease of applying the device to existing flower-pots, flower-boxes, containers, etc. but still entail the problem of a correct warning of the forthcoming exhaustion of the reserve of liquid.
The market calls for an embodiment which is as simple as possible from a constructional standpoint and is therefore cheap and which at the same time is fully functional from the point of view of its application to new or existing usage systems.
Moreover, the devices of the state of the art do not overcome the problem of controlling the level of the liquid inside the tank. This problem is felt in particular where cultivation is carried on with the "ebb and flow" system, since the water in the substratum has to be wholly used up before it can be replenished.
In fact, with this type of cultivation it is necessary to reach almost total dehydration of the cultivation substratum to prevent the occurrence of problems such as asphyxia or decomposition of the roots, with the resulting death of the plant.
This control of level is very difficult to achieve owing to the fact that the tank is not accessible from the outside inasmuch as it is positioned below the cultivation substratum.
Various systems to display the level have been disclosed which employ, for instance, a float, a warning light, an acoustic alarm, etc. , but these systems do not meet the user's requirements.
In fact, the signalling apparatus often remains hidden by the vegetation, or jams, or goes dead or defective and thus prevents proper notification of the remaining stock of liquid.
Furthermore, with the devices of the state of the art it may happen that too much water is added, with a resulting escape of liquid from the overflow since the level of the liquid in the tank cannot be seen.
Moreover, with the devices of the state of the art there is no possibility of regulating the percentage of humidity in the cultivation substratum according to the requirements of water of the plant, for these requirements may vary according to the kind of plant and the climatic conditions.
In particular, everyone knows that plants- need much greater quantities of water in summer than in winter.
With the devices of the state of the art it may happen that in winter, so as to ensure that the cultivation substratum has a modest degree of humidity in order to avoid decomposition, it is necessary to have a smaller quantity of liquid in the main pot.
This situation entails the same problems linked to the knowledge of the level of the water in the tank.
Furthermore, the devices of the state of the art have a great height in proportion to the actual quantity of cultivation substratum which they hold, since the lower part of the main pot is taken up by the tank of liquid, and this fact leads to the use of pots or boxes which are aesthetically unsightly, or else the stock of water is very small and therefore lessens the endurance of the system considerably.